Method and apparatus for packaging powders and the like



Feb. 24, 1959 L. B. ROCKLAND ETAL 2,375,070

METHOD AND APPARATUS FOR PACKAGING POWDERS AND' THE LIKE Fild iOct. 24, 1 955 3 Sheets-Sheet 1 'TO VACUUM OR GAS LINE T0 PNEUMATIC TO PNEUMATIC SYSTE M SYSTE M FIG.

L.B. ROCK LAND L. F. ATKINSON IN V EN TORS ATTORNEYS FIG. 8'

Feb. 24, 1959 L. B. ROCKLAND ET AL 7 METHOD AND APPARATUS FOR PACKAGING POWDERS AND THE LIKE Filed Oct. 24, 1955 3 Sheets-Sheet 2 FIGZ L. B. ROCKLAND L.F. ATKINSON IN V EN TORS & 4 ATTORNEYS Feb. 24, 1959 B. ROCKLAND EIAL 2,875,070

METHOD AND APPARATUS FOR PACKAGING POWDERS AND THE LIKE Filed Oct. 24, 1955 3 Sheets-Sheet 5 ATTORNEY F QUALITY A 4 A A 55 E f POWDER 53 54 53 FIG. II

FIGIO L. B. ROGKLAND L.'F. ATKINSON \INVENTORS BY 56/ r JQW;

FIG. I2.-

"be sealed by applic'ation United a Patent METnon AND APPARATUS FOR PACKAGING I POWDERSAND LIKE Louis Rockland, Pasadena, an d lllawrence F. Atkinson, Arc'adia,Calif., assignors to the United'States of Americaas represented hythe Secretary of Agriculture Application October 24, 1955,"Serial No. 542,531 100mm. c1. 99-111 (Granted under Title 35, UJS. Code(195 2), sec. 266) A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all pur oses of the United States Government, with the power --to 'gr'ant'sublicenses for such purposes, is hereby granted t'o'th'e Governmentofthe United Statesof America.

This invention relates to method and apparatus for packaging materials in containers made of plastic film "o'i' otherpliant sheet material and which are adapted to of thermal or dielectric heating. One particularobject of the invention is the provistem of method and apparatus by means of which containers can be evacuated, or invested with any desired fluid, prior to sealing. Another particular object of the invention the provision of-inethodand apparatus whereby eontainers holding powdery materials can be subjected to vacuum without loss of the material, without damage to the vacuum system and without interference of the powdery material with the sealing operation or the qualityof the seal. Further objects and features and advantages of the inventionwill be apparent from the following description taken in connection with the appended drawing.

In the drawing:

Figs. 1, 2, 3, and are -elevations -of one modification of the packaging device' comingwithin thescope of this invention. The separate figures depict the same device in four phases of operation. Fig. 1 illustrates the device open for =insertionof a container; 'Fig. 2 illustrates the device in the spaced-sealingphase; Fig. 3 illustrates the device in the vacuumizing phase; and Fig. 4 illustrates the devicein the finalsealing phase.

Fig. -5 is'anenl'arged side elevation of the evacuating tube.

Fig. '6 is an enlarged cross section taken onpla'neA-A of Fig. 3.

Fig. 7 is a three-dimensional view (on an exaggerated scale) ofthe spot sealing head 35 andthe container after having been operated on by this head.

Figs. 8 and 9 are cross sectional views taken on planes B-'B and C-C, respectively, of *Fig. 7.

Figs. 10 and 11 depict portions of containers after having been subjected to the spaced sealing operation using alternative forms of spaced seals.

. Fig. 12 depicts a section of a die which maybe employed to produce a herringbone-type of spacedseal.

Within recent years there has been a trend toward increased use of containers made of plastic films for packaging various products. With many types of articles such containers are quite satisfactory and often cheaper and more'attractive thanconventional containers of metal or paper. In some instances it is desirable to package materials under vacuum win an atmosphere of an inert gas. Such type of packaging is desirable for example with foodstuffs which aresusceptible tooxidative changes on storage. Examples of such foods are nuts, bacon, ham, and many other meatproducts, dehydrated fruit orfvegetable juices, dehydrated .potatoes, dehydrated soups, coffee, and so forth. Equipment hitherto availlevel of the material :in thecontainer, are subjected .to

2,875,670 Patented Feb. 24,1959

able forsuch packaging purposes is complex, expensive and slow in operation. For instance, the generally used sealers are of what may beterm'ed the cavity type. "These devices include a cylinder equipped with. a removable lid. The bag containing the ['m'a'tefialto be packaged is placed in the cylinder, the -lid is secured, and all the air in the container is exhausted. The package is sealed While in the cylinderthen the lid is opened and the sealed package removed. Such equipment has the primarydisadvantage that all the air in the cylinder must be evacuated to achieve vacuum within the package. This is naturally a cumbersome technique and the packaging operation is slow because of this fact. Where the package is to be invested with an inert gas, there is consider able wastage of such gas as the entire cylinder must be filled with the gas.

In the copending patent application of L. B. Rockland and L. Atkinson Serial No. 542,532, :filed October 24, 1955, there is described and claimed a novel packaging device which surmountsmany of the disadvantages of prior art devices. One feature of the Rockland and Atkinson device is that only the air in the package itself need be exhaustedto achieve sealing under vacuum. This means that the device of this application can utilize a vacuum pump of smaller size and the attainment of vacuum requires less timebeeause there is much less volume of air to be removed. Where an inert gas or other fluid is to be introduced into the package after evacuation, only that amount of gas which is actually needed in the package is used.

The device of this invention is an improvement on that disclosed in the aforesaid application in that the present device is particularly adapted for the packaging of materials which are of a powdery nature or which contain powdery or otherwise finely-divided solid substances; The significance of this aspect of the invention is explained as follows:

In the packaging of powdery materials whereinvacuum is. employed during a stage of the operations, several problems are encountered. Thus when powdery materials are subjected to vacuum, particlesof the material tend to be lifted together with thepreviouslyoccluded or admixed air towardthe source of vacuum. The degree to which the particles are entrained in the air stream depends on many factors, particularly the size of the particles and their density. This entrainment of particles gives rise to several disadvantages in that part of the material in the container may be lost. Another point is that the particles whichenter the vacuum system may damage the mechanical parts of the vacuum pump-as for example causing corrosion or scoring of the pump cylinder walls, etc. A third point is that if the particles are lifted to the area of the container where the seal is eventually applied, these particles will impair the quality of the seals. Thus if the particles are sucked up and deposited on the walls of the container near the sealing area, they will become embedded in the seal, thus the seam of closure will then be porous and the package will not be gas tight. Thisis especially serious for example where the package is to be sealed under vacuum. In .such case atmospheric pressure will force air into the package through the minute pinholes formed by the particles embedded in theseal. lnmany cases the particles are porous (e. g., potato granules) sothattheair'will be forced through these embeddedparticles into the package itself.

It has now been found thatentrainment or sucking up of powdery materialsduring vacuumizing can be prevented-bya simple technique. Thus in accordance -with this invention the walls of thecontainer, at .a I point be tween the deviceused for evacuating the air and'the top what may be termed spot or spaced sealing. In this operation a series of spaced seals are formed across the width of the container walls, that is, the walls of the container areunited in spaced areas. Preferably, several rows ofspaced seals are'formed, the individual sealsin each row being staggered with respect to the individual seals inadjacent rows. -When this sealing operation is performed the portions of the container walls inthe areas between the seals become bulged or puckered to a minute extent due to the effect of the localized heating during the sealing operation. The localized heating causes'the sealed areas to shrink whereby the sealed areas are pulled slightly toward one another causing an expansion. and

pufling of the unsealed areas of the container walls when the operation is carried out under a slight positive pressure within the container. The net result of this, regardless of .any theoretical considerations, .is that the spaced sealing operations causes the formation of what may be termed a maze r labyrinth of minute tubules between the spaced sealsp When vacuum is applied to the container holding a quantity of powdery material, some of the particles will tend to rise with the air. These particles will however be trapped in the tortuous passages between the spaced seals and will thus effectively be removedfrom the field of action. As a net result, there is no loss of particles, particles are not sucked into the vacuum system and there is no interference withthe gs M.

horizontal plane. A series of springs 14 adapted to exert an outward bias (toward'ja'w 1) against arm 11 is provided within slot 13. Armll is equipped with bolts 14a which act as limit of motion devices to prevent springs 14 from ejecting arm 1,1,outof slot 13.

The means for final sealing of the bag includes anvil 15 protruding from the inner face of jaw 1.' This anvil is metallic for use with an electrical sealing system or is made of silicon rubber, for example, for use with thermal sealing, that is application of a heated blade. Cooperating with anvil 15 is metallic sealing blade 16 carried'by jaw 2. The sealing blade illustrated has a double bagcontacting head and will establish a double seam of sealing across the mouth of the bag. Blades for forming a single seam or more than two seams may be used as desired. Sealing blade 16 may be exchanged for'another of difierent shape by sliding it out of keyway 17.

-A suitable generator of high-frequency electromagnetic waves (not illustrated) is connected via wires 18 .and 19 to jaws 2 and 1, respectively. When the generator is actuated, the current will flowthrough the bag to be sealed at the area of contact between anvil 15 and blade 16 causing the sides of the bag to be fused together.

final sealing of the container. As disclosed hereinafter the spaced seals, or areas of union between the side walls, may take various formsor shapes but to provide in every case-a series of What may be termed tortuous or indirect passages between the sealed areas. Thepuckering effect referred to above has an additional advantage in that this pufiing out of the side walls of the container in the areas where the walls are not sealed together causes the establishment of minute tubules which do not tend to flatten out when vacuum is applied to the container. tubules remain open so that the air in the container can readily pass through them toward the vacuum source.

The'packaging apparatus and the principles of its operation are explained as follows:

Fig. 1 illustrates the sealing device in its open position for reception of a bag to be sealed. The device includes fixed jaw 1 and movable jaw 2. Jaw 2 is adjustably attached by screws 2a to platen 3 which in turn is attached to shaft 3a. This shaft extends through pack- The result is that when vacuum is applied these The mechanism for establishing the spaced seals across the mouth of the. bag includes a secondarymovable jaw 30 mounted on shaft 31. This shaft protrudes into cylinder 32 which is provided with a piston (as in the case of cylinder 5). By controlling the flow of air or hydraulic fluid through pipes 33 and 34, jaw 30 can be moved toward or away from jaw 1. On jaw 30 is mounted a sealing blade 35, the inner surface of which i is provided with a series of protuberant elements, as 'de ing gland 4 in cylinder 5 there being a piston 8 attached to shaft 3a within cylinder 5. At the opposite ends of cylinder 5 arefprovided pipes 6 and 7, these being connected to a conventional pneumatic pumping system (not 'illustrated).' It is evident that by forcing the air into pipe 6 and withdrawing the air through pipe 7, jaw 2 can be moved away from jaw 1. By reversing the flow of air, jaw 2 can be moved toward jawl. Jaws 1 and 2 are preferably made of aluminum, brass or other electrically-conductive metal in the modification in which the bags are electrically sealed, that is, by applying a high frequency current across the bag at the point of sealing. If sealing is to be carried out by thermal means, that is, by application of a heated blade to the bag, then the jaws may be constructed of strong, heat-insulating material. Where the jaws are made of metal, their inner faces may be covered with an electrically-insulating material to prevent accidental shock to the operator. The means for pinching shut the open end of a bag to prevent loss of vacuum or positive pressure in the bag during such operations as spaced sealing, permanent sealing, etc. includes boss 9 mounted on jaw l, this boss being covered with pad 10 made of rubber or other flexible material. Cooperating with these members and located on ,jaw 2 is arm 11 covered with rubber pad 12. Ann 11 .is slidably received in horizontal slot 13 so thatthefarm can move toward or away from 'jaw 1 in a picted in Fig. '7, for forming a series across the walls of the bag.

One'lead of a conventional high-frequency generator (not illustrated) is connected to common terminal 19 on jaw 1-;,the other lead is connected through a switch to terminal 36. The generator supplies the current for forming the spaced seals when blade 35 is pressed against anvil 15. -If the spaced seals are to be formed by applying a heatedblade to the bag, then blade 35 may be provided with conventional device for heating it by a resistance coil or the like. i 1

The means for withdrawing air from the bag 'or introducing a desired fluid therein is described as foll'owsz Upon jaw 1 is bracket 21 on which is pivoted arm-22 which bears tube 23. Spring 23a biases tube 23 away from jaw 1 when the jaws are open. Tube 23 is connected at its upper end through suitable valve arrangementto a source of vacuum :and a source of inert gas or otherfluid desired for introduction into the bag. The lower'portion of tube 23 is flattened as at 24. About the flattened portion is provided a rubber, winglike member 25, see Figs. 5 and 6.

Referring now to Fig. 5, it is seen that tube23connects with barrel 26 provided with perforations 27. The ends of barrel 26 are provided with cages 28, the diameter of these being somewhat larger than'the diameter of barrel 26. Air orqother fluid canpass freely through perforations 27 into tube 23 or through apertures 29 into the open ends of barrel 26 and thence into tube '23;

The operation of the packaging device is described as follows: i Jaws 1, 2, and 30 are open as shown in Fig. '1' and-tube 23 is pivoted away' from jaw. 1 also as. shown in this figure. A bag 4110f polyvinylidene film or the like into which powdery mate'rialhas been deposited is inserted between the jaws so as to envelope the lower portion of tube 23.

A. Formation of the spaced seals (Fig. 2-).The pneumatic system connected to pipes 6. and 7' is actuated to move jaw 2 to the left to the position shown in Fig. 2. At this stage, the power exerted by the pneumatic-sys-. temis so balanced against the expansive bias of-springsx of spaced seals spaced seals are formed,

14mm pads is and 12am ii tight engagement whereas anvillS and sealing blade 16 are a small distancapart. The engagement of pads and -12 causes a closing of "the mouth of bag 40 so that the bag can thenb'e filled with a gas or evacuated. i

The pneumatic system connected to pipes 33 and 34 is then actuated to move jaw and spaced s'ealingblade to the left to the position shown in Fig. 2 wherein blade 35 is pressing bag against anvil 15. Air or other inert gas is then introduced into the bag 40 through pipe 23' to maintain a slight positive pressure therein. By maintaining a positive pressure within the bag during the spaced sealing operation, the formation of tubules between the seals is assured. The source of high frequency current is then connected to terniinals 19 and 36. As a result, the walls of bag 40 are provided with a series of spaced seals 44, and tubules 48, 49 as depicted in Figs. 7 to 9 and as further explained below. As soon as the jaw 30 is retracted to the position shown in Fig. 3.

B. Evacuation of the container *(Fig. 3)-.Jaw 2 is maintained in the positionpreviously described wherein pads 10 and 12 are in engagement 1and thus close the mouth of bag 40. i

Tube 23 is then connected to, a source of vacuum. As the air is sucked out of bag 40, the walls of the bag collapse. However, barrel 26 and cages 28 prevent the c01- lapsing walls of the bag from plugging up the passage way to tube 23. In particulan the walls of the bag are drawn tightly to perforations 27-. As a result the bag is so firmly held that its walls cannot be sucked into apertures 29 with the result that these apertures remain :open and air can pass through them into barrel 26 and into tube 23.

Particles of material 41 whichmay be entrained in the air stream are deflected by the spaced seals formed in the first operation (Fig. 2) and thus do not interfere with the vacuumizing step. c

Referring to Fig. 6 it can be seen that during the evacuation and sealing phases, no air can get into or out of the bag 40 except, of course, through tube 23. Thus the bag is squeezed shut between pads 10 and 12 During these phases the pressureforcing jaws 1 and 2 together also causes pads 10 and 12'to deform ab'oiit wihg-like manner 25 so that no air can leak inaboiit the flattened portion 24 of tube 23 or about the 's'ide's ur ne wiiig 25. The boss 9 and arm 11 are recessed slightly as at 37 aiid 38 to permit deformation of pads 10 ahd 12 to conform to the shape ofwing memberzs. m V i It is obvious that memberss, 10,11, 12, I5, '16, and 35 should have a length (the, diiiiehsion runnin at right angles to the paper on which Figs. 1 to 4 are drawn) greater than the width of bag 40. On the other hand wing 25 should be of less wiclth than the bag so that the bag can easilybe placed about the wing wheh thefpa'ckaging operation is initiated. T e

C. Sealing operiztion (Fig. '4). Afte'r bag 40 has been exhausted, the pneumatic systeincorinected with tube 7 is activated to increase the pressure acting on the right side of piston 8 whereby to overbalance are 'eirpansive force of springs 14. As alresult anvil lS and sealing blade 16 bear against the wall's of bag 40 eiitending between them, as shown in Fig. 4. At this time the source of electrical energy connected to terminals 18 and 19 is turned on and as a result of the heating effect taking place at the point of contact the bag is sealed along seams corresponding with the length of blade 16.

After the sealing has been completed, the pneumatic system of cylinder 5 is activated toinove piston '8 to the -right whereby the sealed bag is released and drops out frombetween jaws 1 and 2. The device is then ready for sealing of the next package. N

The feature of the invention as concerns the use of spaced sealing to deflect particles of material is further explained as follows:

As explained above and as depicted Fig. 2, hag it) is indicia.

subjected tospacedsealingprior to evacuation. This is done byforcirig; sealing bladelas against anvil: is and actuating the high frequency" energy source connected jacross terminals 19 and 36 while the bag is under a slight positive pressure of .gas in the bag. The positive pressure insures proper tubulation of the area around the spaced seals.

, Referring now to Fig. 7, it can be seen that the inner face of sealing blade 35'is provided with an upper row of protuberant elements 42 and a lower row of protuberant elements 43, the individual elements in. one row being staggered with respect to those in the other row. The edges of the elements are rounded to prevent cutting the container walls. (For the sake ofsimplifying the illustration, only five elements are depicted.) When the bag 40, under slight gas-pressure, is compressed between anvil 15 and elements 42 and 43 and the high-frequency electrical source is connected across theanvil and the elements, there is formed the spaced seals indicated as 44 (formed byelements 42) and 45 (formed by elements 43). Within the areas of these seals, the walls 46 and 47 of bag 35 are fused together. The localized heatihg which takes place during the sealing operation causes a shrinkage in the sealed areas whereby the walls 46 and 47 are forced apart and expanded slightly in the nonsealed areas between the seals. As a result there is formeda series of minute tubular passageways 48 between adjacent seals in the same row and similar passageways 49 between seals in adjacentrows (see Figs. Sand 9.). When the bag 40 is evacuated, air can'pass through these tubules along paths indicated'for example by dotted line 50. The entrained particles will be deflected by striking the various portions of the sealed areas as shown by dotted lines 51. his obvious that the number and size of the spaced seals provided will depend onthe flotation (entrainment) characteristics of the material being packaged. It is evident for example that with a material which tends to be floated only to. a mino'r de gree, only a few spaced seals will benecessary. Where however the material is very 'fine or otherwise has a high tendency to be entrained in the air stream the number of rows of spaced seals may be increased to "provide a more tortuous path between *the upper and lower portions of bag 40 whereby a 'more eflicient (lCflGClliOlldOf the particles will be accomplished.

It is also to be noted that the spaced seals need not necessarily be of the shape depicted in Fig. 7. Thus the seals may be of triangular, cubic, or curved pattern, the latter being depicted in Fig. -10. Inthis case the particles striking the lower edges of upperfseals 52 will tend to bounce downward-into the gap between the lower seals 53 as illustrated by dotted line 54.

It is evident that the spaced seals formed on the con tainer become a permanent part of the container since the container is eventually sealed at a point above the spaced seals. Consequently the operation of spaced sealing may be utilized for equipping the package with any To this end the 'protuberant elements 42, 43 on sealing blade 35 may be shaped in the form of letters thus to form sealed areas which spell out a desired mes sage as for example the manufacturers name, etc. Fig. 11 illustrates such a type of operation wherein the letters 55 constitute the spaced seals.

If the package is to be invested with a fluid prior to sealing, the following technique is applied. Bag 40 is exhausted as previously'described then tube 23 is connected with a source of fluid, for example dry air, nitrogen, etc., to introduce this material into the bag while the device is kept in the position of Fig. 3. law 2 is then moved further to the left to cause engagement of the sealing anvil and blade (15 and 16) as shown in Fig. 4 and the sealing is etfectuated as before.

Introduction of aninertgas, such'as nitrogeh, into the container after evacuation and prior to sealing is often desirable with divers foodprodiictsto protect theni fi'drh 7 oxidation, etc. during storagef' 'Als'o by introducin gas of this type the particles 41 will be loose within the package after sealing. If the' package is sealed under vacuum the walls of bag 40 will remain tightly collapsed about the particles 41 so that the package will be a rigid unit and particles 41 will be held tightly together by the pressure of the atmosphere acting on the external walls of the bag." 'Thus' there is a matter of appearance to be considered here as to whether the final package is desired to be limp and contain loose articles (sealed in gaseous atmosphere) or whether the final package is desired as a rigid unit with coherent particles within it (sealed under vacuum).

The invention may be utilized for the packaging of any type of material, particularly materials such as food products which are best'preserved under vacuum or in an atmosphere of an inert gas. The invention is especially adapted for the packaging of food materials which are in subdivided form as for example in the form of powders,

granules, beads, small crystals, liquids, or other particles which exhibit a tendency to be entrained in the leaving air when a package thereof is subjected to vacuum. Ex-

amples of such products are 'dried potato granules; spraydried products of divers types such as spray-dried coffee, tea, tomato juice, orange juice, grapefruit juice, meat juice, soups, etc.; cereal products such as flour, starch,

etc.; andother dehydrated fruit, vegetable, meat, cereal,

or carbohydrate products which are inthe form of fine particles or which contain fine particles in admixture with coarser particles. In regard to the last item, the invention is of advantage in packaging such products for example as candies or dried fruit which contain a surface coating of powdered starch, powdered sugar or mixtures thereof. In such case the powdery coating will not interfere with the packaging operation.

Instead of an inert gas or together with the inert gas, other fluids can be introduced into the package prior to sealing. Thus in packaging food products, after the container is exhausted a stream of nitrogen, dry air or the like may be used as a carrier to introduce divers vapors into the package. In this manner one may introduce vapors of such agents as: antioxidants, for example butylated hydroxyanisole, Nordihydroguaiaretic acid, propyl gallate, and so forth; enzyme-inactivating agents as sulphur dioxide; flavoring agents as volatile fruit essences, essential oils, hickory wood smoke, acetic acid, and so forth; fungicides as propylene oxide; etc. In the case of packaging hardware or other metallic objects, vapors of corrosion-preventing agents may be inserted in the package in the same fashion. Further extensions of these principles will be obvious from the foregoing.

In the preferred modificationof this invention, highfrequency electrical energy is used for sealing the plastic film package. It is obvious that other sealing techniques can be used compatible with the type of film from which the container is made. For example, sealing head 16 may be provided with internal coils heated by passage ofan electrical current whereby head 16 becomes hot and the sealing is effectuated simply by applying thermal heating during the phase when blade 16 and anvil are in engagement. The same type of modification can be applied to spaced-sealing head 35.

For rapid sealing of packages on the device of this invention it is preferred that there be provided rapid-acting mechanisms for actuating the movement of jaws 2 and 30, connection of tube 23 to the vacuum source, connection of tube 23 to the fluid source for adding fluid to the package, activating the high frequency electrical supply .for. spacedsealing and final sealing, etc. To this end there may be provided a series of'push-button switches which operate through relays to activate the various valves and switches to accomplish the proper series of activities." Devices of this type are purchasable on the open market and need not'be described further herein. 7 7

-' f1? In the pro'cess'of packaging divided material in members he covered with a thin film of polyfluoroethylene orothenheat-resistant non-adhesive, synthetic resin.

We claim:

a sacciformcontainer having an open upper end and a closedrlower'end; wherein'aiquantity of the divided material -is de'posited inthe lower end of the container and wherein the container 'is evacuated prior to closure, the improvement which comprises uniting the side walls of the container at spaced areas across the width of the container at a position above the level of material in the container whereby to form a series of small indirect passageways between the areas, and thereafter evacuating the container from a point above said position.

,2. A process of packaging a divided material in a bag-like containerwhich comprises depositing a quantity of the material in the container, uniting the side walls of the container above the deposit of material at spaced areas across thewidth of the container, the areas of union being arranged in such a pattern as to provide a series of small indirect passageways therebetween, evacuating the container from a point above said spaced, united areas and thereafter sealing the container.

3. The process of claim 2 wherein the container is made of thermoplastic sheet material and whereinthe side walls of the container are united by compressing the side walls at spaced areas and applying high-frequency electrical energy at-these areas.

4. A process of packaging a divided material in a bag-like container which comprises depositing a quantity of material in the container, forming a particle deflector in the container intermediate the top of the container and the level of the material therein by uniting the side walls of the container at spaced intervals across the width of the container, evacuating the container from a point above area of union, and thereafter sealing the container.

5. A process of packaging a divided material in a bag-like container which comprises depositing a quantity of the material in the container, forming a particle deflector in the container intermediate the top of the container and the level of material therein by uniting the side walls of the container at spaced areas across the width of the container, the areas of union being in a pattern such that the areas of non-union therebetween define a labyrinthine passageway connecting the section of the container holding the material and the upper end of the container, evacuating the container from a point above the areas of union, and thereafter sealing the container.

6. A process of packaging a divided material inv a bag-like container made of thermoplastic, pliant sheet material which comprises depositing a quantity of material in the container, forming a particle trap within the container intermediate the top of the container and the level of material therein by compressing the side walls of the container at spaced areas across the width of the container and applying high-frequency electrical energy at these areas whereby the side walls of the container are united at spaced areas across the width of the container, the areas of union being in a pattern such that areas of non-union therebetween define a labyrinthine passageway connecting the section of the container holding the material and the upper end of the container, the, side walls of the container between areas of union being puckered outwardly as a result of the uniting procedure to define minute tubules between the areas of union, evacuating the container from a point above the areas of union, and thereafter sealing the container. I V

7. The process of claim 6 wherein the spaced areas of union extend in at least two parallel rows across the width of the container and wherein'the individual areas in one row are staggered with respect to the individual areas in the adjacent row.

8. The process of claim 7 wherein the spaced areas are each in the form of a letter, the areas in the aggregate defining embossed indicia.

9. A food package comprising a container made of thermoplastic, pliant sheet material, a quantity of divided food material in the base of the container, a particle trap within the container intermediate the top of the container and the level of food material therein, said trap being formed by union of the side walls or" the container at spaced areas across the width of the container, the areas of nnion being in such a pattern as to provide a series of small indirect openings therebetween thus to define in the aggregate a labyrinthine passageway connecting the section of the container holding the food material and the upper end of the container.

10. A process of packaging material in a sacciform container of thermoplastic, pliant sheet material having an open upper end and a closed lower end which comprises depositing a quantity of material in the lower portion of the container, compressing together the side Walls of the container at spaced areas across the width of the container at a position above the level of material in the container while applying heat at said spaced areas to cause the side walls of the container to be united together at said spaced areas, the areas of non-union therebetween providing a series of passageways interconnecting the section of the container holding the material and the upper end of the container, evacuating the container from a point above the areas of spaced union, and sealing the container.

References Cited in the file of this patent UNITED STATES PATENTS 2,433,176 Van Epps et al. Dec. 23, 1947 2,720,247 Richens Oct. 11, 1955 2,778,171 Taunton Jan. 22, 1957 

1. IN THE PROCESS OF THE PACKAGING DIVIDED MATERIAL IN A SACCIFORM CONTAINER HAVING AN OPEN UPPER END AND A CLOSED LOWER END, WHEREIN A QUANTITY OF THE DIVIDED MATERIAL IS DEPOSITED IN THE LOWER END OF THE CONTAINER AND WHEREIN THE CONTAINER IS EVACUATED PRIOR TO CLOSURE, THE IMPROVEMENT WHICH COMPRISES UNITING THE SIDE WALLS OF THE CONTAINER AT SPACED AREAS ACROSS THE WIDTH OF THE CONTAINER AT A POSITION ABOVE THE LEVEL OF MATERIAL IN THE CONTAINER WHEREBY TO FORM A SERIES OF SMALL INDIRECT PASSAGEWAYS BETWEEN THE AREAS, AND THEREAFTER EVACUATING THE CONTAINER FROM A POINT ABOVE SAID POSITION. 